Stop, Smell the Crayons : Remember when you used to jump for joy? No? Maybe a dose of Dr. Play is in order.

It’s a Saturday morning and Dr. Play--that’s him in the Wizard of Oz filmstrip necktie, golfer green pants and happy face socks--is skipping about a ballroom of a Marina del Rey hotel.

“Are you having fun yet?” he asks the 30 men and women who’ve sacrificed sleep to come out and play. Well, not yet. But wait.

You’re going to have fun today, promises the doc (Howard Papush)--”even if you don’t want to.” His face lighting up, he asks, “When was the last time you jumped for joy?” A few self-conscious titters.

OK, so the economy’s in the pits, downsizing is rampant, one person’s working for two. So, reasons Papush, was there ever a time when grown-ups so desperately needed to have fun?

Now, close your eyes, everyone, and return to Toyland. Maybe you’ve just come home from school and you’re going out to play. . . .

Opening their eyes, they share. One woman is buckling on her roller skates and “zooming along, feeling the wind. The key to the skates was magic. I wore it around my neck.”

Another is playing baseball in an alley behind her house and “losing the ball in Mr. Grigsby’s peach tree.” A man is diving into the pool at Grossinger’s in the Catskills. It’s the summer of ‘69; he’s just heard that the Mets won the World Series.

Papush brings out a big board onto which he’s tacked a few dozen name tags from his collection of 900. Let your fantasies run wild, he says. Be Babs, Foxy, Romeo, Kiddo, Hulk, Twinkle, Max. He hates Howard, so he’ll be Clay. (Name tags are “a wonderful way for people to hide,” he confides later.)

For three hours, they’re kids again. They hold hands, form a chain and contort themselves into impossible human knots, then untwist by stepping over, under, laughing all the while.

Now it’s musical chairs--with its own twist. Anyone caught without a chair must find a lap. By game’s end, it’s lap upon lap upon lap. No one wins; no one loses.

Story time! Each group of playmates is to make up a bedtime tale, starting with “Once upon a time” and ending “happily ever after.” Each time he yells “Switch!” the next person in the group is to carry on.

Whooping with delight, one group comes up with a whale of a tale that manages to have ants the size of elephants, candy that grows on trees, Godzilla--and a corporate takeover.

Pick a partner, Papush says, time for “car, car.” One partner is the driver; the driver’s hands go on the car’s shoulders. Trust is the key here: The car must keep its eyes closed as it speeds around the room. Papush warns, “This is not bumper cars.”

Honking, stalling, engines humming, the cars dodge one another. Mermaid (Victoria Roberts) and her guide dog, Churchill, play pedestrians. In the spirit, she warns: “You can really be sued big time if you hit a blind person.”

The games ended, playmates linger, reliving the joy. They are a diverse lot: a chiropractor, an airline clerk, a dental hygienist, a special-events coordinator.

“I’m a cynic, and this was way cool,” says Blondie.

“My face hurts,” adds Hoot.

Choo Choo looks around: “This room has become a very comfortable place, and there aren’t that many comfortable places.”

Kids-for-a-day take home Dr. Play’s helpful hints for lightening up: Take some toys to the office. “Smell the crayons. They’ll take you back to when you were 4 years old.” Get out your old Barbie doll and play with her. Play with your food--go ahead, blow bubbles in your milk, smush your mashed potatoes around. Wear outrageous underwear.

“Great fun,” concludes Popcorn (Tom Leahy, personal assistant to Dudley Moore). He chose to be Popcorn because it’s “something so closed up and then we cook it and it opens up”--just as he did today.

“I had a blast,” says Dixie (Eula Pendleton, a Westchester High government teacher). “I need to have more joy in my life.” She adds: “I always wanted a name that ended in E. All names that end in E sound so cute.”

In his job, says Spud (Steve Kohn), a sales and marketing director, he is “constantly confronted with ‘no, no, no.’ This helped me to understand that no is not the worst thing in the world.”

They’d checked their inhibitions at the door, together with their egos. Papush is well pleased. A former TV producer and onetime talent coordinator for “The Tonight Show Starring Johnny Carson,” he began approaching corporations about 10 years ago about putting play into the workplace. But the inner-child movement hadn’t yet taken off and, he says: “They didn’t know what I was talking about.”

He flopped.

Undaunted, he dropped Dr. Delight, renamed himself Dr. Play and, three years ago, started selling his playshops as antidotes to job stress and tools for building group harmony. “Let’s Play Again” clients have included the U.S. Postal Service, Arco, Walt Disney Co., Mattel Toys and Hughes Aircraft.

Look, he says, when the baby boomers retire, it’s going to be a sellers’ market. Employees are going to insist on having a good time on the job.

Papush is packing up his toys. “You teach what you learn,” he says. As a less-than-athletic kid, he learned to make his own fun: “Not only was I the last one picked for the team, but the two captains always had an argument about who was going to take me.”

So, Who’s the Father of These Inventions?

OK, so necessity’s the mother of invention. Did you know you need a baseball cap that’s really a cordless, hands-free telephone? Or eight-bladed scissors for slicing veggies right into your wok? A condom pen with secret storage compartment?

Inventors long on ideas, but short on capital, set up shop at the Invention Convention in Pasadena over the holiday weekend, hoping to find a backer savvy enough to spot their invention as the hottest thing since Velcro.

L.A. Firefighter Christopher Cooper was there with his “Remote Coat,” a bump-proof, pizza-proof remote control cover-up. Bill Cervola of Long Beach was extolling the merits of his E-Z Green, a device to splice into your garden hose for one-step watering and fertilizing.

We were quite smitten with Korean military officer Seon Jin Kwon’s gizmo for urban drivers: A lighted sign that speaks to other motorists from your rearview window. By pushing a button on a remote control box, the driver can say Robber, Sorry, Thank You, Call Cop, Too Close, Follow Me or--this one seems to have lost a little something in the translation-- Be Outrun!

For sheer size, nothing was in a class with the aptly named Inferno, a propane-powered industrial space heater that belches emission-free blasts of air at temperatures up to 2,500 degrees.

Good, but what’s it for ? Ideal for keeping orchards frost-free, defogging runways or de-icing highways, said inventor Darrell Jones of Clackamas, Ore., who’s spent seven years and about $200,000 perfecting his prototype.

The shiny metal canister, two feet in diameter and 10 feet long, resembles those cannons that stuntmen come zooming out of at the circus. Motorists gawked as Jones hauled the Inferno to Los Angeles behind his pickup. Most creative guess: The world’s largest hair dryer.

Back-to-the-drawing board department: A treacherous-looking hard plastic cup holder to hook around your neck for no-hands, no-spills freeway slurping. Then there’s the video art instructor, paint-by-numbers for the TV age. Zip. Press a clear film over the screen, then paint over any image. Instant art. (Acrylics are recommended, in case of spills).

And, finally, we’re sorry we asked. That circular viselike contraption with three long screws? An autopsy apparatus, explained Dr. Samuel Merrill, a coroner from Olney, Md. “It will remove the top of the skull in 30 seconds”--a procedure, he had to explain further, that takes 30 minutes with a hand-held saw. Er, thank you, doctor.